Karl Kissner picked up a soot-covered cardboard box that had been under a wooden dollhouse in his grandfather's attic. Taking a look inside, he saw hundreds of baseball cards bundled with twine. They were smaller than the ones he was used to seeing.

But some of the names were familiar: Hall of Famers Ty Cobb, Cy Young and Honus Wagner.
Then he put the box on a dresser and went back to digging through the attic.
It wasn't until two weeks later that he learned that his family had come across what experts say is one of the biggest, most exciting finds in the history of sports card collecting, a discovery worth perhaps millions.
The cards are from an extremely rare series issued around 1910. Up to now, the few known to exist were in so-so condition at best, with faded images and worn edges. But the ones from the attic in the town of Defiance are nearly pristine, untouched for more than a century. The colors are vibrant, the borders crisp and white.
"It's like finding the Mona Lisa in the attic," Kissner said.
Sports card experts who authenticated the find say they may never again see something this impressive.
"Every future find will ultimately be compared to this," said Joe Orlando, president of Professional Sports Authenticator.
The best of the bunch -- 37 cards -- are expected to bring a total of $500,000 when they are sold at auction in August during the National Sports Collectors Convention in Baltimore. There are about 700 cards in all that could be worth up to $3 million, experts say. They include such legends as Christy Mathewson and Connie Mack.
Kissner and his family say the cards belonged to their grandfather, Carl Hench, who died in the 1940s. Hench ran a meat market in Defiance, and the family suspects he got them as a promotional item from a candy company that distributed them with caramels. They think he gave some away and kept others.
"We guess he stuck them in the attic and forgot about them," Kissner said. "They remained there frozen in time."